A WAF or web application firewall helps protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet. It typically protects web applications from attacks such as cross-site forgery, cross-site-scripting (XSS), file inclusion, and SQL injection, among others. A WAF is a protocol layer 7 defense (in the OSI model), and is not designed to defend against all types of attacks. This method of attack mitigation is usually part of a suite of tools which together create a holistic defense against a range of attack vectors.

By deploying a WAF in front of a web application, a shield is placed between the web application and the Internet. While a proxy server protects a client machine’s identity by using an intermediary, a WAF is a type of reverse-proxy, protecting the server from exposure by having clients pass through the WAF before reaching the server.

A WAF operates through a set of rules often called policies. These policies aim to protect against vulnerabilities in the application by filtering out malicious traffic. The value of a WAF comes in part from the speed and ease with which policy modification can be implemented, allowing for faster response to varying attack vectors; during a DDoS attack, rate limiting can be quickly implemented by modifying WAF policies.

ModSecurity is a popular open-source choice and can be used with Apache Web Server as well as nginx whether you’re running virtual machines or have containerized applications.

Many choices are availble in the cloud. Being a Microsoft Partner, we would propose the Azure Web Application Firewall. The Azure Web Application Firewall is a cloud-native service that protects web apps from common web-hacking techniques such as SQL injection and security vulnerabilities such as cross-site scripting. Deploy the service in minutes to get complete visibility into your environment and block malicious attacks.

We can assess your situation with regards to your goals and implement the best option for you.

Contact us today for a consultation!